| 1. |
- Daianova, Lilia, et al.
(författare)
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Local production of bioethanol to meet the growing demands of a regional transport system
- 2011
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Ingår i: Proceedings of World Renewable Energy Congress 2011, May 2011, Linköping, Sweden.
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Konferensbidrag (refereegranskat)abstract
- : Energy security and the mitigation of greenhouse gas emissions (GHG) are the driving forces behind the development of renewable fuel sources worldwide. In Sweden, a relatively rapid development in bioethanol usage in transportation has been driven by the implementation of national taxation regulations on carbon neutral transport fuels. The demand for bioethanol to fuel transportation is growing and cannot be met through current domestic production alone. Lignocellulosic ethanol derived from agricultural crop residues may be a feasible alternative source of ethanol to secure a consistent regional fuel supply in Swedish climatic conditions. This paper analyzes how the regional energy system can contribute to reducing CO2 emissions by realizing local small scale bioethanol production and substituting petrol fuel with high blend ethanol mixtures for private road transport. The results show that about 13 000 m3 of bioethanol can be produced from the straw available in the studied region and that this amount can meet the current regional ethanol fuel demand. Replacing the current demand for petrol fuel for passenger cars with ethanol fuel can potentially reduce CO2 emissions from transportation by 48%.
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| 2. |
- Guziana, Bozena, 1963-, et al.
(författare)
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SCENARIOS FOR WASTE-TO-ENERGY USE - SWEDISH PERSPECTIVE.
- 2011
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The use of waste for energy purposes becomes increasingly interesting both with respect to waste management and for the energy systems. The decisions on alternative uses of waste for energy are mainly influenced by different policies, waste management, energy supply and use, as well as technologies. Two important issues, namely, a clear priority of waste prevention in waste management within EU and the growing concern for food losses and food waste at global and at national level, shall be carefully considered and addressed. This paper proposes scenarios for waste to energy systems with focus on Sweden and with a broader EU approach is applied: Biofuels Sweden, Electric vehicles and Bioenergy Europe. As baseline for the scenario development inventory of waste-to-energy related policies and goals on international, national, regional and local level as well as inventory of existing scenarios and reports with future trends is made. A low waste availability level is recommended to be included in sensitivity analysis for scenarios.
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| 3. |
- Hellstrand, Stefan, et al.
(författare)
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THE POTENTIAL TO INCREASE SUSTAINABLE GLOBAL GREEN ENERGY PRODUCTION THROUGH INCREASED EFFICIENCY IN MILK AND CATTLE PRODUCTION: - A SWEDISH CASE
- 2009
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Konferensbidrag (refereegranskat)abstract
- This paper addresses the potential of sustainability improvement by increased efficiencyin milk and cattle production. The experience of Swedish improvement over the last half centuryreveals the global potential for the sustainable management of land use, nutrition balance andbioenergy supply.Ruminants are an important part of the global food production system. Ruminantproduction has the potential to substantially increase land area available for bioenergy production.They can use energy in foodstuffs with none human nutritive value and simple nitrogencompounds in the production of high quality feeds. They can convert renewable natural resourcesfrom ecosystems, that otherwise have low capacity to transform solar energy fluxes to food, tohigh quality food.Globally, the area of pasture is 2.5 times larger than the area of cropland. Ruminants arean important part of the global food system, supplying human energy metabolism. Due to thecompetition for land, the skilfulness in rumen production affects potentials for green energyproduction supplying the energy metabolism in the technical systems of society.This paper discusses two aspects of ruminant production affecting the potential for greenenergy production:(i) The impact of increased nutritional physiological efficiency, i.e., better feedingstrategies, and(ii) The importance of utilising ruminants as ruminants, where they transform solar energyfluxes to high quality foodstuffs from ecosystems with low capacity to produce food throughother paths.The focal point is the impact on the land remaining for green energy production supplyingthe technical systems of society, after food supply needs are met. Estimates are provided on theimpact on other sustainability aspects at different system levels as well as in the threesustainability-dimensions. The results are provided through the application of a methodologywithin the frame of integrated assessment for analysis of sustainability effects in systems withmutual dependencies between systems and system levels. This is of general interest as amethodology, supporting the development of sustainable green energy production and meetingthe needs of society. It contributes with concrete results, supporting an increased sustainableproduction of green energy due to increased efficiency within a sector that competes for land
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| 4. |
- Hu, Yukun, et al.
(författare)
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Numerical investigation of heat transfer characteristics in utility boilers of oxy-coal combustion
- 2014
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Ingår i: Applied Energy. - : Elsevier BV. - 0306-2619 .- 1872-9118. ; 130, s. 543-551
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Tidskriftsartikel (refereegranskat)abstract
- Oxy-coal combustion has different flue gas composition from the conventional air-coal combustion. The different composition further results in different properties, such as the absorption coefficient, emissivity, and density, which can directly affect the heat transfer in both radiation and convection zones of utility boilers. This paper numerically studied a utility boiler of oxy-coal combustion and compares with air-coal combustion in terms of flame profile and heat transferred through boiler side walls in order to understand the effects of different operating conditions on oxy-coal boiler retrofitting and design. Based on the results, it was found that around 33 vol% of effective O-2 concentration ([O-2](effective)) the highest flame temperature and total heat transferred through boiler side walls in the oxy-coal combustion case match to those in the air-coal combustion case most; therefore, the 33 vol% of [O-2](effective) could result in the minimal change for the oxy-coal combustion retrofitting of the existing boiler. In addition, the increase of the moisture content in the flue gas has little impact on the flame temperature, but results in a higher surface incident radiation on boiler side walls. The area of heat exchangers in the boiler was also investigated regarding retrofitting. If boiler operates under a higher [O-2](effective), to rebalance the load of each heat exchanger in the boiler, the feed water temperature after economizer can be reduced or part of superheating surfaces can be moved into the radiation zone to replace part of the evaporators.
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| 5. |
- Jiang, M., et al.
(författare)
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Performance analysis of a photovoltaics aided coal-fired power plant
- 2019
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Ingår i: Energy Procedia. - : Elsevier Ltd. - 1876-6102. ; , s. 1348-1353
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Konferensbidrag (refereegranskat)abstract
- In this article, integration of photovoltaics (PV) into a coal-fired power plant was proposed. The performance including economic analysis and environmental impact was conducted by a case study in the northwest area of China. The results show that the PV system can replace part of auxiliary power consumption using renewable electricity to reduce internal power consumption and the emissions. Due to the feature of the integration into a power plant, the curtailment of solar PV electricity does not occur compared to stand-alone PV system. The investment cost, operation and maintenance (O&M) expenditure were feasible compared with other PV power generation plants.
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| 6. |
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| 7. |
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| 8. |
- Si, P., et al.
(författare)
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An innovative building envelope with variable thermal performance for passive heating systems
- 2020
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Ingår i: Applied Energy. - : Elsevier Ltd. - 0306-2619 .- 1872-9118. ; 269
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Tidskriftsartikel (refereegranskat)abstract
- The integration of passive solar heating strategies into the existing buildings has been considered as an innovative and effective approach to mitigate energy and environmental issues. To balance the trade-off between solar heat gain and thermal insulation in traditional passive solar systems, this paper presented an innovative envelope with variable thermal performance for passive solar buildings. Field measurement was carried out to validate the feasibility of the transparent building envelope under step control operation strategy to building comfortable indoor environment especially in cold plateau areas. The experimental results show that, even under harsh climate conditions, the application of the proposed building envelope effectively increases the heat gain and maintains indoor temperature at a relatively comfortable level in the studied case. The average indoor air temperature of the studied rooms is at 13.0–14.0 °C, with the highest temperature up to 21 °C. Numerical simulation by DesignBuilder software was further developed to exploit the efficiency of the proposed building envelope under the step control operation strategy for increasing the indoor temperature. The simulation results show the same tendency with the filed measurement results. The operation strategy of opening indoor window at 10:00 am and closing at 5:00 pm can achieve the maximization of solar gain, significantly increasing the indoor temperature. Attributed to good balance between solar heat gain coefficient and thermal resistance, the average temperature of the room with the proposed envelope mode is 2.0 °C (sunny day) and 1.5 °C (cloudy day) higher than that of another three passive solar envelope operation modes, respectively. In general, the proposed building envelope with variable thermal performance has high potential to improve the indoor thermal environment in cold plateau areas at low cost. © 2020 Elsevier Ltd
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| 9. |
- Vassileva, Iana, et al.
(författare)
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Interactions between power producers and customers
- 2009
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Konferensbidrag (refereegranskat)abstract
- In the future we can expect new types of more interactive communications between singlecustomers and groups of customers towards the energy market companies. These can be developas a result of the introduction of individual metering of electricity, and then utilize thisinformation both for information to the customers, as well as different kind of control of thepower system. The information can be through interactive displays where instant and aggregatedenergy and power utilization is presented, but also with a possibility to react to differences inprices by e.g. shutting of some power consumers to avoid high costs. Different types ofinteractions are discussed in the paper.
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| 10. |
- Wang, Weilong, et al.
(författare)
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A new mobilized energy storage system for industrial waste heat recovery for distributed heat supply
- 2009
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Konferensbidrag (refereegranskat)abstract
- This paper introduces a new mobilized thermal energy storage (M-TES) for the recovery ofindustrial waste heat for distributed heat supply to the distributed users which have not beenconnected to the district heating network. In the M-TES system, phase-change materials (PCM)are used as the energy storage and carrier to transport the waste heat from the industrial site to theend users by a lorry. A technical feasibility and economic viability of M-TES has been conductedwith the comparison of the district heating system as a reference. Thermal performance and costimpacts by different PCM materials have been analyzed compared, aiming at determining theoptimum operation conditions. A case study is investigated by utilizing the waste heat from acombine heat and power (CHP) plant for the distributed users which are located at over 30kilometers away from the plant. The results show that the M-TES may offer a competitivesolution compared to building or extending the existing district heating network.
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